Category Archives: Software

Pixel peeping fallacies

Lightroom, Nikon bodies, Technique

Know what you are looking at.

When I migrated from the 12mp Nikon D700 to the 24mp D3x, I did a bunch of thinking about the justification for more pixels.

If you do not propose increasing your print size or cropping more severely, more pixels will likely not serve you well. I contemplate making both larger prints and cropping more when needed. Thus, the higher pixel count sensor makes sense for my contemplated needs.

When I first uploaded D3x images from the D3x to Lightroom, I naturally previewed images at 1:1 and remember thinking “What’s the big deal? This does not look any better than the files from my D700 at 1:1.”

The problem, of course, is that I was not comparing like with like.

Here’s a simple table to illustrate the issue.

I have compiled data for four common Nikon sensors – the math is brand-independent, it’s just that I know these bodies and have RAW images from all. I enlarged these original images using the 1:1 preview function in LR4 and measured the image width on my 21″ Dell 2209WA (1650 x 1080) display. So in the table above, using the D2x as an example, the 12.2MP sensor delivers an image which, if printed 1:1, would be 47″ wide.

What does Adobe’s Lightroom mean by 1:1? It means that images displayed 1:1 are displayed at 90 pixels/inch – you can confirm this by dividing the ‘Sensor – W’, the pixel count across the width of the sensor, by the ‘Width at 1:1 in inches’ and in each case you will get 90 dots per inch. That’s good for an LCD display or for prints looked at from a reasonable distance. If you want to stick your nose in the print, then you want to limit the pixel density to 240 pixels/inch, which is the same as dividing the above ‘Width at 1:1 in inches’ data by 2.7. So a 240 pixels/inch print from the D800’s sensor, for example, would be 31″ wide (83/2.7). But in practice, you do not need that high a density in huge prints.

As you can see, comparing a D700 image with, say, a D800 image, is not fair if identical 1:1 preview ratios are used. You are comparing a 46″ wide image with one almost twice as large at 83″. To make the sensor comparison fair, you need to preview the D800 image not at 1:1 but at 1:2. That will yield approximately the same reproduced image size, making for an objective comparison of resolution and noise if the same lens and technique are used for both.


Preview options in Lightroom.

Yet, I suspect, many snappers fall afoul of these erroneous 1:1 comparisons concluding:

  • I need better lenses with the newer body
  • My images are blurred, I need to use faster shutter speeds
  • My focus is out, there’s something wrong with the camera

All of the above lead to much time and money wasted in fixing the unfixable. Bad data.

It is indeed quite likely that your new sensor out-resolves the limits of your older lenses at 1:1. It’s also reasonable to expect motion blur to be more visible at the same shutter speeds if you use faulty comparisons. And the chances are it’s your technique not your hardware which accounts for poor focusing, the errors only becoming visible at double your former preview magnifications. But, unless you contemplate making crops to one quarter of the area of your previous sensors or making prints 7 feet wide instead of 4 feet wide, your sensor upgrade is only causing you needless pain.

My first conclusion with the D3x compared to its D700 predecessor was all of the above, until I figured out what I was looking at. Some comparisons are easily drawn. It’s clear for example, that the D700 has lower noise than the D2x for the same image size, hardly surprising as we are comparing a recent FF sensor with an older APS-C (D2x) one. The total pixels and 1:1 print sizes are almost identical. On the other hand, comparing the D700 at 1:1 with the D800 at 1:2, for like print sizes, shows little difference. It’s only when you double preview sizes with the D700 to 2:1 and the D800 to 1:1 that you see the greatly superior resolving power of the D800, as the number of pixels you are looking at in such a comparison is tripled in the case of the newer sensor.

Nikon has not helped the situation. After their affordable high pixel count FF bodies – the D600 and D800 – came to market, they started publishing pieces intimating that only their very costliest and newest lenses were ‘good enough’ to extract the best from the new sensors. The rest of the sheep writing purportedly critical analysis followed right along. It’s called sales and makes little sense. Some of Nikon’s highest resolving power lenses were made ages ago, long before digital sensors existed – any Micro-Nikkor macro lens pretty much qualifies (55, 105 and 200mm) – as do a host of pre-Ai lenses, many over four decades old. If you like the latest and greatest (and costliest) have at it. But don’t believe everything you read from such conflicted sources. Their primary focus is not on your image making capabilities but on your wallet, be it through sales (Nikon) or click-throughs (the whores who parrot this stuff as if it was technically proved fact).

So before you chuck out your old lenses and start buying costly superspeed exotics which allow the use of faster shutter speeds, while contemplating return of the body to Nikon for repair of focusing errors, ask yourself what you are really looking at when you preview those enlarged images on your display.

Practical implications: It’s not like you can avoid buying new gear with lots of megapixels by trying to save money on something with fewer. Everything has lots of pixels today. 12MP is hard to find at the lower limit. But the practical implication of this rapid technological advance is that, for those on a budget, substantial savings can result from buying the previous generation of hardware, comfortable in the knowledge that while 8-12MP may not be a lot, it’s more than enough for 99% of needs. DSLR bodies like the Canon 5D, Canon 5D MkII, Nikon D700, Nikon D2x, Nikon D3 and others no less capable from Pentax and Sony offer tremendous savings just because they have been replaced with something that measures better in a comparison table. Heck, a lightly used 6mp Nikon D1x can be had for under $250 and will offer tremendous capability, outfitted with a $50 mint MF Nikkor, far in excess of the abilities of most. The barrier to entry to good hardware has never been lower. 16″ x 20″ prints? No problem. Why do I say that? The D1x’s sensor is 3,008 pixels wide, so for a 90 pixel/inch print (what Lightroom shows at 1:1 preview) you would get a print sized 33″ x 22″. Unless you stick your nose in it, it will show just fine.


Nikon D1x. Add Nikkor of choice.

DxO ViewPoint

Lightroom

A handy plug-in.

DxO is a Photoshop or Lightroom plugin whose purpose is twofold. Correcting keystoning from leaning verticals or slanting horizontals and removing volume anamorphosis, the elongation of objects near frame’s edge when very wide angle lenses are used. I have traditionally used PS CS5 to correct keystoning and believe that PS CS6 adds volume anamorphosis correction, but as DxO is running a $39 special offer – half off – through December 31, 2012, I purchased the Mac version on the recommendation of a friend.

DxO’s poky servers went down half way through my first download attempt but the second was successful. It’s a whopper at some 187MB, larger than Lightroom itself. You have the option of installing it as a PS and/or LR plugin in addition to the mandatory stand-alone version which is installed in the Applications folder.

The LR version integrates seamlessly, requiring the user to hit Photo->Edit in->DxO Viewpoint when in the Library or Develop module whereupon LR generates a lossless TIFF file which pops up in DxO ViewPoint. You have a choice of 32-bit or 64-bit versions. I went into Finder and erased the 32-bit one as it’s a distraction. If you can use 64-bit, why not?

The controls are intuitive. In the image below from the San Francisco Palace of Fine Arts, there is keystoning in two planes – vertical, obviously, and horizontal as I was not plane to the subject.

There are three keystoning icons in addition to traditional sliders. Icons are the way to go. First you dial in your preferred aspect ratio – 3:2 like the original in this case – then click on the double keystoning icon and align the guidelines with the two verticals and two horizootals that have to be straightened:


Guidelines aligned along two verticals and two horizontals.

Click Accept then File-Save and the corrected version is saved, stacked, along your original in LR:


Corrected version.

Here’s the result after using the Transform->Distort command in PS CS5 for comparison:


Corrected in Photoshop CS5.

Note the excessive elongation of the plinth compared with the DxO ViewPoint corrected version. I have left in a hint of keystoning in both versions to preserve the suggestion of great mass and height.

Either version is better than the rudimentary correction in Lightroom, which tends to remove far too much of the original.

I don’t know that I would pay $79 for this plugin but $39 seems fair. As I do a fair amount of architectural photogrtaphy, it fills a niche in the toolbox. Whenever taking pictures where keystoning is unavoidable, I make sure to include lots of space around the main subject, knowing that much of it will be lost in processing.

Original on the D700, 35-70mm f/2.8 AFD Nikkor.

Nikon voice memos

Lightroom, Nikon bodies

Smooth Lightroom integration.

One really handy feature in the Nikon D2/D3/D4 bodies is the ability to record a voice memo of up to sixty seconds in length for each image. After enabling the function in Settings, you hold the voice memo button down while speaking into the microphone on the rear of the body. If you are taking posed snaps of strangers and want to send them a copy as a courtesy, this is a great way of recording their email address for later retrieval.

At first I thought this to be a worthless gimmick but in practice am finding it to be a really useful feature on my D2x.


Recording button red circle; speaker and microphone – yellow and green arrows.

You can playback the voice memo using the camera’s small speaker to check it’s intelligible at the time of recording.It sounds far better over your computer’s speakers!

When it comes to processing, Lightroom fully accommodates this function. The WAV file recording has the same frame number as the image but with a ‘.wav’ file extension and is imported along with the image into LR 2, 3 and 4.

You can see the sound file in the Library module of Lightroom and you can play it back by clicking the arrowed icon:


LR’s Develop module and the playback icon.

A like feature is also available on some Canon DSLR bodies.

File sizes? A 10 second recording averages 75MB – not enough to worry about when it comes to consuming precious space on your camera’s CF or SD card. The D2 and D4 use one CF card, the D3 one or two CF cards.

Software of the Year

Lightroom

No contest.

By a country mile, Adobe’s Lightroom is my choice as Software of the Year.

While Lightroom has been around for quite a while, it has continually moved to strength and has never become a resource hog. It runs very fast on a capable machine, be it Mac or PC, yet will perform at quite usable speed on something more modest like my 2012 MacBook Air. Photoshop deserves like praise for speed; I’m still on CS5.

For cross-platform users, the LR catalog will load just fine in Windows and in OS X, and Adobe’s realistic licensing permits use on two machines. While it was hard to imagine any great improvements to LR3, LR4 surprised mightily with it’s greatly enhanced Highlights, Shadows, Clarity and Vibrance technologies, all materially improved from version 3. Used creatively, the first two begin to approximate the power of HDR with none of the complexity or garish results. Add a touch of noise suppression from the built-in controls and you have pretty much all you could wish for in day-to-day processing. With an outstanding database with easy keywording and filtered image retrieval, you are looking at a very powerful tool indeed. Aftermarket apps to load images to Shutterfly or to offer specialized processing needs are easily added. I find I rarely leave the confines of Lightroom for my processing needs, with round trips to Photoshop generally being restricted to perspective correction (PS’s tools are more powerful than LR’s) and, of course, to selectively blur backgrounds with the excellent Magic Lasso tool and Filter->Blur->Lens Blur. It would be great if Adobe was to add these functions in LR, but I suspect cannibalization of their PS cash cow is a key concern.


This merely scratches the surface of the metadata capabilities of Lightroom.

The one other external processing tool I use occasionally is Snapseed, which now accepts TIFF files generated from RAW originals, meaning no loss of quality. I use LR4 with two displays and it is beautifully engineered for this purpose.

Having chipped my many old MF Nikkors, I especially like how LR reads the EXIF data and automatically invokes the appropriate lens correction profile from the many I have created. It just takes one more bit of drudgery out of the processing step.

Best of all, LR is remarkably inexpensive for what you get, which includes Book, Map, Slideshow (really outstanding) and Print modules, all well integrated, for $115 at Amazon. The best book I have found is by Martin Evening who not only writes and illustrates his instructions well, but also takes great photographs. A $33 bargain which really should come with the software.

Update 12/17/2012:

This just hit my inbox. At $129 there are few better bargains in photographic software:

A fortnight with Mountain Lion

OS X

Robust and trouble free.

I published some early performance data for Mountain Lion on the Hackintosh a couple of weeks ago here, having earlier cautioned against early adoption owing to possible incompatibilities with older 32-bit applications.

Thus I determined to run Mountain Lion off back-up drives on three machines – the 2012 MacBook Air and my two Hackintoshes, HP100 and HP10. The latter pair use Gigabyte Z68X-UD2H-B3 motherboards, with Nvidia 9800GTX+ and GT430 twin monitor graphics cards, respectively. HP100 adds a third monitor via a DisplayLink USB dongle. The HP100 sports an i7 Sandy Bridge CPU, overclocked from 3.4GHZ to 4.4GHZ and the HP10 makes do with a modest i3 Sandy Bridge which cannot be overclocked, but serves just fine for streaming market data.

During the past two weeks I have used all three machines heavily at both my day job where I invest money and for processing my pictures using LR 4.1 and PS CS5.

It’s been pretty smooth sailing. All app vendors whom I favor have made sure their apps work with Mountain Lion with the natural exception of Xrite which prides itself on always being last, claiming they need to ‘test more’, even though Mountain Lion has gone through four Developer Previews in the six months before release. But that’s hardly news coming from a monopolist in the field of colorimeters – Huey, Eye1, Spyder – all Xrite, sadly. Still, while they screw around and generally act in their usual inept manner, you can be comforted with the knowledge that the Eye 1 display profiling app works perfectly fine with Mountain Lion, no thanks to Xrite, and likely unknown to them ….

As of today I am switching to Mountain Lion as the production OS on those three computers. It has proved bug free, robust and some of the enhancements are more than just eye candy. The addition of AirPlay, which permits anything on your screen to be routed to your TV to which an AppleTV is connected, is a tremendous value added and has all the TV companies searching for a change of underwear. Notifications and the ability to tailor these easily to your preference, are another great iOS feature which was overdue on the desktop. Safari is greatly improved, which probably says more about how dated it was with Lion, and installing Mountain Lion on a Hackintosh has never been easier. Overall speed may be a smidge slower than with the last version of Lion but it’s no big deal and my experience has shown that Apple generally speeds up a major OS as minor releases come along. CPU operating temperatures are unchanged from those seen in Lion.

I have had only one glitch and that was self-inflicted. The i7 Sandy Bridge overclocks easily up to 4.4GHz from 3.4GHz in stock form and when importing pictures and generating 1:1 previews in Lightroom on HP100, while simultaneously developing the early imports (hey, why wait?) I got a kernel panic. Turning down the CPU clock by some 2.5% to 4.3GHz solved the issue and while I could easily get to 4.5GHz or higher by messing with core voltages and a myriad of other variables in the BIOS, the return on effort and lower life span of the CPU mean I will not be going there. The machine is as fast as can be for my purposes.

So there are two messages from this experience:

  • Once you are satisfied that your favorite apps will work, it’s safe to upgrade
  • There has never been a better time to build a Hackintosh